ACE/apps/JAWS2/JAWS/Cache_List_T.h

   1 /* -*- c++ -*- */
   2 #ifndef JAWS_CACHE_LIST_T_H
   3 #define JAWS_CACHE_LIST_T_H
   4
   5 #include "ace/Malloc.h"
   6 #include "JAWS/Cache_Object.h"
   7
   8 // Forward declarations
   9 template <class EXT_ID, class FACTORY, class HASH_FUNC, class EQ_FUNC>
  10 class JAWS_Cache_Manager;
  11
  12 template <class EXT_ID, class FACTORY, class HASH_FUNC, class EQ_FUNC>
  13 class JAWS_Cache_List_Item;
  14
  15
  16 template <class EXT_ID, class FACT, class H_FN, class E_FN>
  17 class JAWS_Cache_List
  18 // Roll my own heap here.  Eventually, a heap should be its own
  19 // standalone data structure.
  20 //
  21 // This version is not a heap, but a doubly linked list.  We are
  22 // trying to simplify all the heap operations to be O(1).
  23 {
  24 public:
  25
  26   typedef JAWS_Cache_Manager<EXT_ID, FACT, H_FN, E_FN> Cache_Manager;
  27   typedef JAWS_Cache_List_Item<EXT_ID, FACT, H_FN, E_FN> Cache_List_Item;
  28
  29   JAWS_Cache_List (ACE_Allocator *alloc = 0, size_t maxsize = 8192);
  30   // maxsize is the total number of objects the in memory cache is
  31   // willing to manage
  32
  33   ~JAWS_Cache_List (void);
  34
  35   int is_empty (void) const;
  36   int is_full (void) const;
  37
  38   size_t size (void) const;
  39   size_t maxsize (void) const;
  40
  41   int maxsize (Cache_Manager *cm, size_t new_maxsize);
  42   // attempt to grow (or shrink) the heap.  Return 0 on success, -1 on
  43   // error.
  44
  45   int insert (const EXT_ID &ext_id, JAWS_Cache_Object *const &int_id);
  46   // attempt to insert int_id into heap.
  47
  48   int remove (EXT_ID &ext_id, JAWS_Cache_Object *&int_id);
  49   // attempt to remove the top element of heap.
  50
  51   int remove (void *item);
  52   // treat item as a Cache_List_Item, and remove it from the heap
  53
  54   int adjust (void *item);
  55   // treat item as a Cache_List_Item, and alter its heap position
  56
  57 protected:
  58
  59   void insert_i (Cache_List_Item *item);
  60   // insert item into heap.
  61
  62   void remove_i (Cache_List_Item *item);
  63   // remove the element residing at pos, but do not delete it.
  64
  65   void remove_i (void);
  66   // remove the element residing at the top of heap, but do not delete it.
  67
  68 private:
  69
  70   ACE_Allocator *allocator_;
  71
  72   size_t maxsize_;
  73   size_t size_;
  74
  75   Cache_List_Item *item_;
  76
  77   Cache_List_Item *head_;
  78   Cache_List_Item *tail_;
  79
  80 };
  81
  82
  83 template <class EXT_ID, class FACT, class H_FN, class E_FN>
  84 class JAWS_Cache_List_Item
  85 {
  86
  87   friend class JAWS_Cache_List<EXT_ID, FACT, H_FN, E_FN>;
  88
  89 public:
  90
  91   typedef JAWS_Cache_List<EXT_ID, FACT, H_FN, E_FN> Cache_List;
  92
  93   JAWS_Cache_List_Item (const EXT_ID &ext_id, JAWS_Cache_Object *const &int_id);
  94   unsigned int priority (void);
  95
  96 private:
  97
  98   EXT_ID ext_id_;
  99   JAWS_Cache_Object *int_id_;
 100
 101   JAWS_Cache_List_Item *next_;
 102   JAWS_Cache_List_Item *prev_;
 103 };
 104
 105 #if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
 106 #include "JAWS/Cache_List_T.cpp"
 107 #endif /* ACE_TEMPLATES_REQUIRE_SOURCE */
 108
 109 #endif /* JAWS_CACHE_LIST_T_H */